Assessing the Background Rate due to Cosmic Ray Core Scattering from Internal Reflection Layers in the South Pole Ice Cap

Radio-based neutrino detectors using a surface architecture, based on the ARIANNA concept, search for upward-traveling radio signals generated by high-energy neutrinos in the polar ice. The surface station envisioned for IceCube-Gen2 consists of both upward and downward facing LPDA antenna, which are directional. In this contribution, we investigate one potential background that generates radio signals from the same (upward) direction. At South Pole elevations, there is a significant flux of cosmic ray cores above 1017eV that strike the snow surface and generate Askaryan-like radio signals within the upper 10 m that travel downward through the ice. The polar ice also contains multiple reflective layers at depths of 300-1200 m. These layers reflect back the downward-traveling radio background and represent a novel source of radio background for future ice-radio cosmogenic neutrino detectors. We provide an assessment of the background rate at a surface station due to the reflected core radio signals. We also provide analysis of tagging the cosmic-ray cores by observing the concurrent radio signal generated in the atmosphere with the upward facing LPDA antennas.